-'Stack exchange' in the header to view messages/hot topics
-'show other means of login' on login page
-vote
-rich text edition isn't available

if it can be of any use, here's some console output:

stub.js:11Uncaught SyntaxError: Variable 'g' has already been declared
ask:21Uncaught ReferenceError: StackExchange is not defined
ask:68Uncaught ReferenceError: StackExchange is not defined
ask:76Uncaught ReferenceError: StackExchange is not defined
ask:178Uncaught ReferenceError: StackExchange is not defined
ask:219Uncaught ReferenceError: StackExchange is not defined
ask:242Uncaught ReferenceError: StackExchange is not defined
ask:269Uncaught ReferenceError: StackExchange is not defined
ask:317Uncaught ReferenceError: StackExchange is not defined
ask:374Uncaught ReferenceError: StackExchange is not defined

Even if that's legal, as it appears to be the case, I'm not sure that's a good idea. I consider it highly confusing what the Closure compiler does there, but oh well…

Anyway, the most important point: The error you're seeing was a browser bug. More precisely, it was a bug in V8 (Chrome's JavaScript engine) that was fixed a long time ago. In Chromium/Chrome 20, it doesn't appear, even with the experimental setting enabled. So just update your browser, and you should be fine (or leave experimental JS disabled).